Most county naturalizations are in the office of the prothonotary, although some are in city or county archives, such as those for Philadelphia and Chester counties. A few of these records have been published, such as those for Allegheny (1798–1906), Bucks (1802–1906), Philadelphia (see below), and Westmoreland (1802–52). Provincial, state, and other records are in the state archives, including those of the supreme court, most of which were published in Pennsylvania Archives, 2d series, vol. 2, and reprinted as Persons Naturalized in the Province of Pennsylvania, 1740–1773 (Baltimore: Genealogical Publishing Co., 1967, 1991). For other records at the archives, see Dructor’s Guide listed under Pennsylvania Archives, Libraries and Societies.

Non-British subjects in Pennsylvania were required to take an oath to the province, and their names are found in Strassburger/Hinke noted above. Records of oaths of loyalty to Pennsylvania’s Revolutionary government are found in Thompson Wescott, Names of Persons Who Took the Oath of Allegiance to the State of Pennsylvania Between … 1777 and 1789 (1865; reprint, Baltimore: Genealogical Publishing Co., 1965). Many nineteenth-century Philadelphia records are located through P. William Filby, ed., Philadelphia Naturalizations: Records of Aliens’ Declarations of Intention and/or Oaths of Allegiance, 1789–1880 (Detroit: Gale Research Co., 1982), which reproduced an earlier compilation by the Historical Records Survey (1941). This should be used with Jefferson M. Moak’s “The WPA Index of Naturalizations: An Explanation,” The Pennsylvania Genealogical Magazine 36 (1989): 109-16.

Federal court naturalizations are at the National Archives—Mid-Atlantic Region in Philadelphia and cover petitions for courts in Philadelphia (1790–1991; indexed, 1795–1990), Pittsburgh (1820–1979; indexed, 1820–1990), Erie (1940–72), Harrisburg (1911–17), Scranton (1901–90), Wilkes-Barre (1943–72), and Williamsport (1909–13), as well as an index to the latter four courts (1901–90).